Make it whiskey

A man walks into a bar. The bartender says to the guy, "What can I get you?"

"Make it a whiskey," says the man, who promptly throws it down in one gulp.

"That'll be three dollars," says the bartender.

"Screw you!" says the man. "You offered to get me something. I thought you were paying."

"Get out," says the bartender. "You're banned. I don't need your crap."

Two years later, the same man walks into the same bar with the same bartender. The bartender looks at him and says, "You're the jerk who tried to con a drink out of me, aren't you?"

"Excuse me, but I have no idea what you're talking about," says the customer. "I've never been to this bar before in my life!"

"Sorry. My mistake," says the bartender. "You must have a double."

"Hey thanks, dude!" says the customer. "Make it whiskey."